Flame resistant composition of abs, polyarylene polysulfone and bromo-aryl compound

ABSTRACT

Thermoplastic blend of ABS, polyarylene poly-sulfone resin (e.g. condensation product of the dipotassium salt of 2,2-bis-(4hydroxyphenyl) propane and 4,4&#39;&#39;-dichlorodiphenyl-sulfone), and bromo-aryl compound (hexabromobenzene or hexabromodiphenylether), with or without antimony oxide, is self-extinguishing, has high heat distortion temperature, and good processing characteristics.

Elnited States Patent Hinckley et a1. 5] Aug. 22, 1972 [54] LAMERESISTANT COMPOSITION ()1? 3,555,119 1/1971 Ingulii et a1 ..260/876 ABS,POLYARYLENE POLYSULFONE 3,472,799 10/ 1969 Burger et a1 ..260/876 UND3,442,980 5/1969 Grabowski ..260/880 AND BROMO ARYL C 0MPO 3,075,944 l/1963 Wick et a1. ..260/41 [72] Inventors: Paul D. Hmckley, Woodbury;

Gerald J- Klender, Naugfituck, both Primary Examiner-Samuel H. Blech ofConnfi Jerry Lamblotte West Assistant Examiner-Helen W. RobertsAttorney-James J. Long [73] Assigncc: Uniroyal, Inc., New York, NY.

, l 57] ABSTRACT 221 Filed: May 22, 1970 lhermoplastlc blend of ABS,polyarylene poly-sulfone 1. 1 pp 39,631 resin [c.g. condensation productof the dipotassium salt of 2,2-bis-(4-hydr0xyphenyl) propane and 4,4- 52us. Cl.....260/876 R, 260/45.7 R, 260/45.75 R, 5dichlorodiphenyl-sulfonel7 and bromo-aryl Compound 260/49, 260/887,260/893, 260/D1G. 24 (hexabromobenzene or hexabromodiphenylether), 51int. Cl. ..C08f 41/12, C08f 45/58 with or without antimony Oxide, isself-extinguishing, [58] Field of Search ..260/876, 880, 893 has highheat distortion temperature, and good processing characteristics. [56]References Cited 21 Claims, 1 Drawing Figure FLAME RESISTANT COMPOSITIONOF ABS,

POLYARYLENE POLYSULFONE AND BROMO- ARYL COMPOUND BACKGROUND OF THEINVENTION 1. Field of the Invention This invention relates to aflame-resistant thermoplastic composition.

2. Description of the Prior Art Thermoplastic blends of ABS gum plasticwith polyarylene polysulfone resins are disclosed in US. Pat. No.3,555,1 19, Jan. 12, 1971,1ngu1lietal.

US. Pat. No. 3,442,997, Grabowski, May 6, 1969,

discloses a blend of an ABS graft polymer and SUMMARY OF .THE INVENTIONCertain blends of ABS gum plastic with polyarylene polysulfone resindisclosed in the prior art unfortunately are not as flame retardant aswould be desirable in some applications. The present invention is basedon the discovery that by addition of bromo-aryl compound to the blend,thermoplastic resin compounds with excellent self-extinguishingproperties are produced without significantly altering the desirablephysical or chemical properties of the unmodified blends, and, in fact,the processing characteristics are significantly improved whileretaining high heat distortion temperature and excellent impactstrength.

BRIEF DESCRIPTION OF THE DRAWING In the accompanying drawing, the singleFIGURE is a graph representing flow properties as determined in arecording plastometer.

DETAHJED DISCLOSURE The expression ABS gum palstic is used herein in itsconventional sense to designate the known thermoplastic polymericcompositions containing combined acrylonitrile, butadiene, and styrene,also called ABS resins or ABS graft copolymers, described for example inUS. Pat. Nos. 2,439,202, L.E. Daly, Apr. 6, 1948; 2,600,024, H. Romeyn,Jr. et a1., June 10, 1952; 2,820,773, C.W. Childers, Jan. 21, 1958;3,111,501, M.S. Thompson, Nov. 18, 1963; 3,198,853, R.L. Bergen, Jr.,Aug. 3, 1965 and 3,261,887, J.U. Mann, July 19, 1966. As is well knownto those skilled in the art, the ABS plastic may be of the graftcopolymer type, or of the physical blend type (polyblend), or acombination' of the two. The conventional ABS graft copolymers are madeby graft copolymerizing resinforming monomers, such as styrene andacrylonitrile, on a previously prepared polybutadiene rubber spine,

or a butadiene-styrene copolymer rubber spine; in the final graftcopolymer the resinous portion and the rubbery portion are in partchemically combined. The socalled graft copolymer in actual practicecontains some ungrafted resin, that is, not all of the resin-formingmonomers become grafted to the rubbery spine polymer in the course ofthe graft polymerization process. The graft copolymer may be made by anemulsion polymerization technique, in which a previously prepared latexof polybutadiene or similar rubber, which serves as a spine, is subjectto emulsion polymerization conditions with a monomeric mixture ofstyrene and acrylonitrile emulsified therein. Alternatively, graftcopolymer may be prepared by solution polymerization methods, or byso-called bulk-suspension technique. On the other hand, the physicalblend type of ABS is typically a mixture of butadieneacrylonitrilerubber with separately prepared styreneacrylonitrile resin. Frequentlythe graft polymer type of ABS includes additional separately preparedstyreneacrylonitrile resin blended with the graft copolymer. Any suchtype of ABS resin is suitable for blending with the thermoplasticpolysulfone resin in accordance with the invention. Moreover, ifdesired, other styrene-type monomer (such as alpha-methylstyrene) may besubstituted for some or all of the styrene itself and other acrylicmonomers (such as methacrylonitrile, ethyl acrylate, methylmethacrylate) may be substituted for some or all of theacrylonitrile-type monomer.

Since the ABS material has both a rubbery component (e.g. polybutadieneor butadiene-styrene spine or butadiene-acrylonitrile copolymercomponent) and a resinous component (styrene-acrylonitrile), it maytherefore be regarded as a gum plastic type of material. Usually theproportion of the rubbery component in the ABS is from 5 to 35 percent,while the proportion of resin is correspondingly from 95 to 65 percent.The overall proportion of acrylonitrile, butadiene and styrene-typemonomer usually falls within the ranges: 10 to 40 percent acrylonitrile;5 to 65 percent butadiene; and 25 to 85 percent styrene.

The MS. Thompson US. Pat. No. 3,111,501, referred to above as disclosingABS resins of the kind employed in the invention, is directed to thetype of ABS made by blending alpha-methylstyreneacrylonitrile resin witha graft copolymer of styrene and acrylonitrile on polybutadiene. Thus,for example, there may be employed in this invention the compositionsmade by blending alpha-methylstyrene/acrylonitrile resin (69/31)(Thompson, col. 2, lines 34-35) with a graft copolymer ofstyrene/acrylonitrile (70/30 ratio) monomers on polybutadiene latex (46percent styrene/acylonitrile and 54 percent rubber solids) (Thompson,col. 3, lines 32-37). Thompson also discloses, at col. 1, lines 68-70,that some or all of the styrene in the graft copolymer may be replacedby alpha-methylstyrene. Likewise, Mann US. Pat. No. 3,261,887, col. 5,lines 48, 49; col. 10, Tables 6 and 7; col. 11, lines 50, 51, 54, 55discloses alpha-methylstyrene as the comonomer with butadiene to makealpha-methylstyrene-butadiene copolymer spine for grafting, whileGrabowski US. Pat. No. 3,130,177, col. 4, lines 13-15, disclosesreplacement of the styrene, in part or entirely, byalpha-methyl-styrene, in the preparation of the graft copolymer.Similarly, the R.L. Bergen, Jr., U.S. Pat. No. 3,198,853 referred topreviously shows ABS containing graft copolymer of styrene andacrylonitrile on polybutadiene blended with separately prepared formscontaining sulfone linkage; if E is so selected as not to contain asulfone linkage, then E must be selected from one of the formscontaining a sulfone linkage. Of course, E and E may both containsulfone resinous copolymer of alpha-methylstyrene and 5 linkages ifdesired. Typical preferred polymers are acrylonitrile. Thus, at column2, lines 39-42, Bergen,

Jr., discloses blending the graft copolymer with I separately preparedresinous copolymer of styrene or alpha-methylstyrene and acrylonitrile.At column 4, lines 6-12, Bergen Jr., discloses a blend of 35 parts of agraft copolymer of 50 parts of styrene and acrylonitrile (ratio 70/30)on 50 parts of polybutadiene rubber, blended with 65 parts of separatelyprepared resinous copolymer of alpha-methylstyrene and acrylonitrile(ratio 69/31). Any such types of ABS may be employed in this invention.

The polysulfone resin component of the blend may be described as alinear, thermoplastic polyarylene polyether polysulfone, wherein thearylene units are interspersed with ether and sulfone linkages.Reference may be had to U.S. Pat. No. 3,264,536, H.B. Robinson et al.Aug. 7, 1966, British Pat. No. 1,060,546, 1967, Minnesota Mining andManufacturing Co., and U.S. application, Ser. No. 847,427, R.J. Cornellfiled Aug. 4, 1969, for descriptions of such resins. These resins may beobtained by reaction of an alkali metal double salt of a dihydric phenoland a dihalobenzenoid compound, either or both of which contain asulfone linkage SO between arylene groupings, to provide sulfone unitsin the polymer chain in addition to arylene units and ether units. Thepolysulfone polymer has a basic structure composed of recurring units ofthe formula:

wherein E is the residuum of the dihydric phenol and E is the residummof the benzenoid compound having an inert electron withdrawing group inat least one of the positions ortho and para to the valence bonds; bothof said residua are valently bonded to the ether oxygens througharomatic carbon atoms; at least one of said residua (E or E or both)provides a sulfone linkage between aromatic carbon atoms. Suchpolysulfones are included within the class of polyarylene polyetherresins described in U.S. Pat. No. 3,264,536, referred to above, thedisclosure of which is hereby incorporated herein by reference for thepurpose of describing and exemplifying E and E in more detail, includingthe preferred forms of E derived from dinuclear phenols having thestructure:

as defined therein, with the further limitation that either or E must beso selected, from the values of E and E disclosed in said patent, as tocontain a sulfone linkage to provide sulfone units in the final polymerchain. Thus, if E is so selected as not to contain the sulfone linkage,then E must be selected from one of the composed of recurring unitshaving the formula:

as described in the Robinson et al. patent, particularly 15 ing of abond between aromatic carbon atoms and a divalent connecting radical andR represents a member of the group consisting of sulfone, carbonyl,vinyl, sulfoxide, azo, saturated fluorocarbon, organic phosphine oxideand ethylidene groups and Y and Y may be the same or different and eachrepresent inert substituent groups selected from the group consisting ofhalogen (fluorine, chlorine, bromine or iodine), alkyl groups havingfrom one to four carbon atoms and alkoxy groups having from one to fourcarbon atoms and where r and z are integers having a value from 0 to 4inclusive, with the further proviso that at least one of R and R must beSO Typically R is representative of a bond between aromatic carbon atomsor a divalent connecting radical and R represents sulfone. Preferably Rrepresents a bond between aromatic carbon atoms. Even more preferred arethe thermoplastic polyarylene polysulfones of the above formula whereinr and z are zero, R is a divalent connecting radical of 5 the formula:

0 wherein R represents, as exemplified in Robinson et 50 bisphenol ofbenzophenone (4,4-dihydroxydiphenyl ketone), or the bisphenol oracetophenone 1,1-bis-(4- hydroxyphenyl) ethane], or the bisphenol ofvinyl cyclohexane l-ethyl- 1 -(4-hydroxyphenyl )-3-( 4-hydroxphenyl)cyclohexane], or 4,4'-dihydroxydiphenyl sulfone (seeExamples 1, 3, 4, 5 and 7 of Robinson et al.), or alpha, alpha-bis(4-hydroxyphenyl)-p-diisopro pylbenzene (see copending application, Ser.No. 847,427 of R.J. Cornell referred to above). Further usefuldiscussion of the polysulfone resins which may be used is to be found inBritish Pat. No. 1,060,546, referred to above. Ordinarily at least about10 percent and preferably at least about 20 percent of the linkagesbetween the arylene groups are sulfone groups:

Apart from the ether and sulfone linkages, arylene groups may be bondeddirectly to each other or may be separated by inert groups, e.g.,alkylidene groups such as isopropylidene groups, which latter appear inthe chain when bisphenol A [2,2-bis(4-hydroxyphenyl) propane] is used inthe preparation of the polysulfone.

In most cases, the relative proportions of ABS plastic to polysulfoneresin range from to 90 parts of ABS, and correspondingly from 90 to 10parts of polysulfone resin per 100 parts by weight of ABS pluspolysulfone. A preferred range for the amount of polysulfone resin inthe blend is from 30 to 70 parts by weight, with correspondingly from 70to 30 parts by weight of ABS material. In general the blend preferablycontains at least 48 parts by. weight, most preferably about 48-60parts, of polysulfone resin.

The foregoing known blends v of thermoplastic polysulfone resin with ABSgum plastic are characterized by a combination of useful properties,particularly high heat distortion temperature, excellent impact strengthand ease of processability. However, even though the polysulfone resinitself is self-extinguishing by such tests as the UnderwritersLaboratories Subject No. 746 test (formerly UL No. 94), ABS-polysulfoneresin blends containing sufficient ABS to impart the most desirablephysical properties do not perform as well as would be desired in thisstringent test. The present invention is, as indicated, directed torendering the blend remarkably self-extinguishing, and the inventionaccomplishes this by including in the blend a bromo-aryl compound,particularly the fully brorninated benzene, hexabromobenzene, orhexabromodiphenylether, also known as hexabromodiphenyloxide. The lattermay be represented by the formula:

If desired, additional materials which contribute to flame-retardency,such as anitmony oxide, may be incorporated into the blend along withthe bromo-aryl compound. By the addition of hexabromobenzene orhexabromodiphenylether, with or without antimony oxide, to theABS-polysulfone resin blend, thermoplastic resin compositions withexcellent self-extinguishing properties are produced withoutsignificantly altering the physical or chemical properties of theunmodified blends. Furthermore, processing characteristics of theself-extinguishing blends as measured by Mooney viscometer or byBrabender plasticorder are significantly improved. This effect isunexpected because the addition of hexabromobenzene orhexabromodiphenylether to ABS-type polymers causes a considerablereduction in the impact strength especially at concentrations whichproduce effective flame retardancy.

To prepare the blend of the-invention, the two starting polymers,namely, ABS material and thermoplastic polyarylene polysulfone resin,and the hexabromobenzene or hexabromodiphenylether, with or withoutother ingredients such as antimony oxide are mixed together with the aidof any suitable mixing device conventionally used for mixing rubbers orplastics, such as a differential roll mill or an internal mixer. Inorder to facilitate thorough mixing of the polymers and to develop thedesired improved combination of physical properties, the mixing iscarried out at elevated temperatures, sufficient to soften the polymersso that they are thoroughly dispersed and intermingled with each other.The mixing temperature will in general vary with the particular ABS andthe particular polysulfone employed; usually the polysulfone, which isthe higher-softening material, will govern the mixing temperatureselected. The mixing is continued until a uniform blend is obtained. Theorder of addition of the ingredients may be suitably varied as desired.In one procedure for making the self-extinguishing blend oftheinvention, all of the ingredients are charged initially to a mixer,such as a Banbury, intensely mixed, then sheeted out on a mill, andconverted into a convenient form for example by dicing. According toanother procedure, the two resins are mixed until fluxed, and thebromo-aryl compound (as well as antimony oxide or other ingredients ifdesired) is added, and further mixed. Alternatively, the two resins maybe blended, sheeted and diced, and thereafter returned to a mixer wherethe bromo-aryl compound (with antimony oxide if desired) is added andmixed in thoroughly.

The proportion of hexabromobenzene or hexabromodiphenylether in theself-extinguishing resin composition of the invention may vary,depending particularly on such variables as the degree offlame-resistance desired, the particular polysulfone resin employed, andthe amount of polysulfone resin in the blend, and the presence orabsence of other substances contributing to flame-retardancy, such asantimony oxide. For purposes of the invention there is usually employedat least about 2 parts of hexabromobenzene or hexabromodiphenylether perparts by weight of ABS resin plus polysulfone resin in the blend.Frequently the hexabromobenzene or hexabromodiphenylether content willvary from about 4- parts to 14 parts. While there is no critical upperlimit to the amount of hexabromobenzene or hexabromodiphenyletheremployed it is usually not necessary or desirable to use more than about20 parts. In those compositions of the invention which do not includeantimony oxide the content of hexabromobenzene or hexabromodiphenyletherpreferably varies between 4 and about 14 parts. In those compositions ofthe invention which contain antimony oxide the hexabromobenzene orhexabromodiphenylether content usually varies between about 4 parts and14 parts, preferably 4 to 7.5 parts. The antimony oxide usually variesbetween about 1 and about 8 parts, and is preferably within the range of1.5 to 5 parts. Within the ranges stated it will usually be found thatthe best results in the flammability tests are achieved by thecombination of highest polysulfone resin content, highest sulfonecontent in the polysulfone resin and highest concentration of bromo-arylcompound and antimony oxide. With the blends of relatively low sulfonecontent (whether because they contain a low amount of polysulfone resin,or whether because the polysulfone resin has a small content of SOlinkages, or both it is particularly desirable to recurring units havingthe structural fomula:

use a high content of bromo-aryl compound. Converse- It may be preparedin accordance with Example 1 of 1y, low contents of bromo-aryl compoundare more the Robinson et a]. patent referred to above. suitably employedin compositions containing a high Blends of 50 parts of the ABS plasticand 50 parts of amount of sulfone (whether because of the presence of 10the polysulfone resin are prepared by mechanically a large amount ofpolysulfone resin, or because the mixing the two materials in a Banburymixer at 460 F polysulfone resin has a high content of -SO linkfor threeminutes. These blends are sheeted off on a ages, or both). 350 F milland diced.

Various flammability tests may be used to measure The ABS polysulfoneblend material is recharged to the burning characteristics of theplastic compositions the Banbury and fluxed at 350 F to obtain a melt.Hexof the invention. Two tests accepted by the plastics inabromobenzene,or hexabromobenzene with antimony dustry are the UnderwritersLaboratories t st N 746 oxide, are added, to provide a series of blendshaving and the General Electric flammability index test. These varyingamounts of the flame-proofing agents. The hextests give reproducible relt hi h. ar i f l abromobenzene contains 87 percent bromine. The anfromthe standpoint of end-use applications, and they t ny Oxide is a m r ialpr parati n known as provide both a qualitative and quantitative measureof ogard S, Containing 83.5 percent antimony. The

flammability. The compositions of the invention are reresulting blendsare Sheeted OffIOII 8 0 F mi and markable for their ability todemonstrate excellent diced- This i g e d i termed a double flammabilityproperties in such tests, as well as re- Processlng techmquesistance toimpact and high temperatures, along with Test Specimens are P p yinjection molding improved flow and processing characteristics. The theVarious blends using a standeld Screw machineprovision of such acombination of properties in a Flame test Specimens in thleknees arereasonably priced thermoplastic resin composition fills P p ycompression molt-finge Properties e an important commercial d, 3 thevarious formulations may be found in Table 1. It IS A further im rt tadvantage of h flam resistant important to note that a thermoplasticcompound rated blends of the invention resides in their ability to sub-Self-extinguishing y the Underwriters Laborastantially maintain theirinitial color during processing. tofies 746 Flammability Test, resultswhen 10 P This is true especially if heat stabilizers (e.g., the cone yWeight e e 9 5 Percent y Weight bromine ventional tin mercaptidestabilizers well known in the Wlth antlmony oxide 15 Incorporated Intothe p f plastics industry) are incor t d blend. The improvement in theGE. Flammability The following examples, in which all quantitie ar IndexRating from 22.5 percent for the unmodified expressed by weight, willserve to illustrate the practice blend t0 Percent for the blendeonteining 5 P of the invention in more detail, cent by weight brominewith antimony oxide, as shown 40 in Table 1, further illustrates theexcellent self-extinguishing characteristics of the modified blend.These EXAMPLEI self-extinguishing ratings are obtained withoutsacrificing high heat distortion temperature (measured by The ABSemployed in this example contains 22.5 ASTM method D648-56 [1961]) orother physical percent acrylonitrile, 26.5 percent butadiene, and 51properties, i.e., impact, tensile, flexural strengths, etc. percentstyrene-type monomer (18 percent styrene it- In fact, processability asmeasured by Mooney viscosity self and 33 percent alpha-methyl-styrene).It is made ,(Table I) and by a Brabender Plasticorder (see thebyblending 53 parts of graft copolymer with 47 parts of drawing) of theself-extinguishing blends is improved separately preparedalphamethylstyrene-acrylonitrile such that the compounds may beprocessed at lower (/30 ratio) resin. The graft is a copolymer of 34parts 50 i temperatures. In the graph shown in the drawing the styreneand 16 parts acrylonitn'le on 50 parts of poly results of BrabenderPlasticorder examination of two (butadiene-costyrene) (/10 ratio) rubberspine. samples are shown. The data are for 50 gram samples, Thethermoplastic polysulfone used is a commerat a speed of 120 RPM,temperature 450 F. The upper cially available resin supplied by UnionCarbide Cor- 5 curve is obtained on acontrol stock similar to Stockporation (Polysulfone P-1700) and is composed of 1 of Table 1,containing no flame retardant additives.

TABLE I [Self-extlngushing ,AB S/polysulfone blends] Stock I-l I-2 I-3I-4 I-5 1-5 Forulation (parts):

1. 50% ABS/50% polysulfone 89. 65 87. 35 95. 54 92. 42 80. 39

2. Hexabromobenzene (87% Br) 10. 35 12. 65 3. 45 5.75 s. 05

3. Antimony oxide (83.5% Sb) 1.01 1. 83 2. 5G Bromine analysis, percent7. 93 11. 02 3. 55 5.02 6. 94 Antimony by wet ash test, percent 0.09 015 0. 22 0. 91 1. 44 2. '20 Hardness, Rockwell R t 114 115 115 1.14 116116 Notched izod, 5 at RT, ft.-lbs. per in 13. 2 10.3 9. 6 11. G J. 50.5 Notched izod, at 20 F., ft.-ll s. per 111....... 2. 3 2. 6 2. 3 1. 82.0 1. SJ I-IDI, 264 p.s.i., annealed, F 270 264 283 275 284 291 Tensilestrength, psi. 90 800 7, 640 7, 840 7 860 7, 820

similar to Stock I- 5 of Table I, containing the flame resistantadditives. The superior processability of the composition of theinvention is apparent.

Example I may be repeated, using an ABS containing 51 percent styreneitself as the styrene-type monomer, in place of 18 percent styrene, 33percent alphamethy1styrene(i.e., the separately prepared resin is astyrene-acrylonitrile copolymer rather than analphamethylstyrene-acrylonitrile copolymer). The example may be repeatedusing other polysulfone resins, such as that derived from alpha,alpha'-bis (4-hydroxyphenyl)- p-diisopropylbenzene and4,4-dichlorodiphenyl sulfone (see Ser. No. 847,427).

EXAMPLE II In this example, the same ABS and the same polysulfone areused as in Example I, but the mixing technique is varied in the severalstocks shown in Table II. In 3 stock 11-5, the same processing techniqueis used as in TABLE 111 Example I, called the double processingtechnique. In [Varoius additives in self-extinguishing ABS polysulfoneblends] stocks II1 and II-3 a processing technique called the Stock H14H14 11H one-shot technique 1s employed. This involves chargingFormulation (parts) initially all ingredients to the Banbury andintensely 35 1. 5o ABs 5o% o1 s1 nn e 9 2. 1 89.30 84.47 2.Hexabromobenzene 87 r inixmg ftor approxnlnately 3 nunutes 121261011118temtplera g ia z fig gig (67% 5 fi U 6 X 4. ecac oro in any r 0 t eml(mettemper%ture),ls The en 6. Antimony oxide (83.5% sb 1.83 1.85 5.15 isthen sheeted off on a 350 F mill and diced. Stocks Percent brpmlneanallysls 4.78 4.46 mu Percent h 01 a sis II-2 and H4 util ze what istermed the incremental 40 geHifntgngZTni E1y y IitAJH test. 1. 42 1. 4.

or ness, 00 we techmque to whlch the polysulione and Notched lzod,} atRT, it.-lbs. perin... 10.0 5.8 9.2 ABS are charged initially to theBanbury mixer. The Notchedizod, 5/." at -20, .4m. per in... 1.2 polymersare mechanically worked until fiuxed at 460 33 8,364 7, 200 F. At thistime the chemical additives (hex- T011911) mdulus, Mooney viscosity at450 1 42 38 30 abromobenzene-antimony oxide) are charged and Appearance,color Tenn thoroughly mixed into the melt for one minute. The 45 $111mm", SE 1 SE1 blend IS then sheeted off on a 350 F null and diced.Horizontal SE SE 34) Table II shows that the properties of the resultingblends are not significantly altered by the compounding techniques.

M TABLE I-(onlinuud [Self-extlngushing ABS/polysulfone blends] Stock I-l1-2 I-3 14 L5 I-5 Tensile modiilus, p.s.i. 10 3.1 a. s a. o 3.0 a. o 2.8 Flexural strength, p.s.i.Xl0 0, 180 10, 420 10, 560 11,000 10,900 10,980 Mooney viscosity at 450 F., ML-5. 57 43 41 52 46 Vertical Mu B-D -0SE 1 B-D SE 1 SE 1 Horizontal, MW"... BD 1.63 SE SE SE SE SE (LE.flammability index 22. 5 30.0 GNorEs.B-D=burns and drips; BC=burns andignites cotton; SE=self-extinguishing; SE 1=self-ext.,

roup 1.

The lower curve is obtained on a stock of the invention, EXAMPLE IIIhigher processing temperatures required when han-.

dling the blend. To demonstrate this, blends of the polysulfone and ABSplastic of Example I with tetrabromophthalic anhydride (Stock III-2 inTable III) and decachlorobiphenyl (Stock III-3 in Table HI) are preparedby the double processing mixing technique. Sample specimens of theseblends prepared by screw injection molding are discolored and initialsigns of degradation are evident. The blends do not demonstratesufficient thermal stability for commercialization. In addition,physical and flame properties are not comparable to those of the blendsof the invention (Stock III-l; also Tables I and II).

1 Light tan.

2 Brown (degraded).

NOTE.-BD=burns und drips; li-ND=burns and non-dripping;SE=selI-extinguishing; SE basil-extinguishing Group 1.

TABLE II [Self-extinguishing ABS/polysulfone blends mixing techniques]Stock 11-1 11-2 11-3 11-4 II-5 Formulation (parts):

1. 50% ABS/50% polysulfone 87. 35 92.42 92. 42

2. Polysulfone 43. 46. 21

3. ABS 43,68 46.21

4. llexabromobenzene (87% Br) 12.65 12 5.75 5.75 5.75

5. Antimony oxide (83.5% Sb). 1.83 1. 83 1. 83 Bromine analysis, percent9, 96 11 1 5.18 5.11 4.78 Antimony by wet ash test percen 1. 74 .60 1. 4Compounding technique Incr Incr. Hardness, Rockwell R 112 113 113 113114 Notched ixod, at RT, it.-lbs 8.8 8. 8 8. 2 8. 8 10.0 Notched ixod, Vat -20 F., ft.-lbs. peri 2.1 2.3 1.8 1.7 9 HD'I, 264 p.s.l., annealed, F264 271 284 285 285 Tensile strength, p.s.i 7, 320 7, 340 7, 500 7, 4607, 020 Tensile modulus, p.s.i. 10 3. 2 3. 4 3. 4 3. 4 3. 5 Flexuralstrength, p.s.i.X10 10, 580 10,280 10,750 10, 660 11,330 Mooneyviscosity at 450 F., MLX-5 33 31 37 42 UL #746:

Vertical, Me SE 1 SE 1 SE 1 SE 1 SE l Horizontal, Me SE SE SE SE SE G.E.flammability index 20. 7 30. 3 30.0

1 One shot. Double proc.

N orE.SE=se1f-extingulsh1ng; SE 1=seli-extinguishing, Group 1.

EXAMPLE IV tions to the valence bonds, where both Using the same ABS andpolysulfone resin as in Exemployed is a commercial preparation known asNC-l90l (Dow Chemical) having a molecular weight of 639.4, containing74.5 percent bromine. It is in the form of a white solid, having amelting point of 170 C and a decomposition point of 415 C. Thermalgravimetric analysis results C/min.) are reported as: 10 percent, 285C;50 percent, 335 C. The properties of blend are given in Table IV. TheGeneral Electric oxygen index flammability test is performed, giving anoxygen index of 28.7 for the described blend, as compared to a value ofonly 21-22 for a similar ABS- of said residua are valently bonded to theether oxygens through aromatic carbon atoms, and at least one of E and Eprovide a sulfone linkage between aromatic carbon atoms.

4. A composition as in claim 1 wherein (A) is composed of recurringunits having the formula:

wherein R represents a member of the group consisting of a bond betweenaromatic carbon atoms and a divalent connecting radical and R representssulfone, Y and Y each represent inert substituent groups selected fromthe group consisting of halogen, alkyl groups having from one to fourcarbon atoms and alkoxy groups having from one to four carbon atoms andwhere r and z are integers having a value from 0 to 4 inclusive.

5. A composition as in claim 1 wherein (A) is composed of recurringunits of the formula:

polysulfone resin blend not containing the additives oi the invention. 7

Table IV Use of Hexabromodiphenylether in ABS-Polysulfone Blend 50%ABS/50% Polysulfone 9L6 parts Antimony oxide (83.5% Sb) 1.8 parts HBDPE6.6 parts l/8"Notched lzod at R.T. 10.5 ft-lbs. per in. 1/8" Notchedlzod at -20F 1.8 ft-lbs. per in. Hardness, Rockwell R 1 14 Heatdistortion temp. 280F Tensile Strength 7660 psi Tensile Modulus 3.1 X 10psi Oxygen Index 28.7

Having thus described our invention, what we claim and desire to protectby Letters Patent is:

l. A synthetic thermoplastic resin composition comprising a blend of IA. from to 70 parts by weight of a linear thermoplastic polyarylenepolyether polysulfone resin, B. correspondingly from 70 to 30 parts byweight of acrylonitrile-butadiene-styrene polymeric materiwherein E isthe residuum of a dihydric phenol and E is the residuum of a benzenoidcompound having an inert electron withdrawing group in at least one ofthe posi- 6. A composition as in ciaiiiii'iiiiiiihiit a part i of thestyrene in (B) is replaced by alpha-methylstyrene.

7. A composition as in claim 1 in which (B) comprises a graft copolymerof styrene and acrylonitrile on a rubbery spine selected frompolybutadiene and butadiene-styrene copolymer.

8. A composition as in claim 1 wherein (A) amounts to 48-60 parts and(B) amounts to correspondingly 52-40 parts.

9. A composition as in claim 1 in which (C) is hexabromobenzene.

10. A composition as in claim 1 in which (C) is hexabromodiphenylether.

11. A composition as in claim 1 in which (C) is hexabromobenzene andantimony oxide.

12. A composition as in claim 1 in which (C) is hexabromodiphenyletherand antimony oxide.

13. A composition as in claim 1 wherein (A) contains alkylidene linkagesbetween arylene groups.

14. A composition as in claim 5 in which (E) comprises a m ixture of (I)a graftpopol er of styrene and acrylonitrile on a rubbery spine se ectedfrom polybutadiene and butadiene-styrene copolymer, and (Il) separatelyprepared alpha-methylstyrene-acrylonitrile resin.

15. A composition as in claim 14 in which (C) is hexabromobenzene.

16. A composition as in claim 14 in which (C) is hexabromodiphenylether.

17. A composition as in claim 14 in which (C) is hexabromobengeneandantimony oxide.

18. A composition as in claim 14 in which (C) is hexabromodiphenyletherand antimony oxide.

19. A composition as in claim 7 in which (B) contains separatelyprepared alpha-methylstyreneacrylonitrile resin.

20. A composition as in claim 19 wherein (A) amounts to 48-60 parts and(B) amounts to correspondingly 52-40 parts, and the bromo-aryl compoundis hexabromobenzene.

21. A composition as in claim 19 wherein (A) respondingly 52-40 parts,and the bromo-aryl comamounts to 48-60 parts and (B) amounts to oorpoundis hexabromodiphenylether.

, mg? sTATEs Puma ower I CERTIFICATE OF CORRECTION v mm No. 3,686,362August 22, 1972 Inventofls) Paul D. Hinckley et a1. 1

It; is certified that error appears inthe above-identified patent andthat said Letters Patent are hereby con-acted as shown below:

Column 12, line 46, for the claim reference numeral "1", read --2- 6Signed and sealed 'th-is 22nd day of May 1973.

(SEAL) Attest:

EDWARD M;FLETCHER,JR. ROBERT GOTTSCHALK I Commissioner of PatentsAttesting Officer

2. A composition as in claim 1 in which at least 20 percent of thelinkages between the arylene groups in (A) are sulfone groups.
 3. Acomposition as in claim 1 wherein (A) is composed of recurring unitshaving the formula -O-E-O-E''-wherein E is the residuum of a dihydricphenol and E'' is the residuum of a benzenoid compound having an inertelectron withdrawing group in at least one of the positions ortho andpara to the valence bonds, where both of said residua are valentlybonded to the ether oxygens through aromatic carbon atoms, and at leastone of E and E'' provide a sulfone linkage between aromatic carbonatoms.
 4. A composition as in claim 1 wherein (A) is composed ofrecurring units having the formula: wherein R represents a member of thegroup consisting of a bond between aromatic carbon atoms and a divalentconnecting radical and R'' represents sulfone, Y and Y1 each representinert substituent groups selected from the group consisting of halogen,alkyl groups having from one to four carbon atoms and alkoxy groupshaving from one to four carbon atoms and where r and z are integershaving a value from 0 to 4 inclusive.
 5. A composition as in claim 1wherein (A) is composed of recurring units of the formula:
 6. Acomposition as in claim 1 in which at least a part of the styrene in (B)is replaced by alpha-methyl-styrene.
 7. A composition as in claim 1 inwhich (B) comprises a graft copolymer of styrene and acrylonitrile on arubbery spine selected from polybutadiene and butadiene-styrenecopolymer.
 8. A composition as in claim 1 wherein (A) amounts to 48-60parts and (B) amounts to correspondingly 52-40 parts.
 9. A compositionas in claim 1 in which (C) is hexabromobenzene.
 10. A composition as inclaim 1 in which (C) is hexabromodiphenylether.
 11. A composition as inclaim 1 in which (C) is hexabromobenzene and antimony oxide.
 12. Acomposition as in claim 1 in which (C) is hexabromodiphenylether andantimony oxide.
 13. A composition as in claim 1 wherein (A) containsalkylidene linkages between arylene groups.
 14. A composition as inclaim 5 in which (B) comprises a mixture of (I) a graft copolymer ofstyrene and acrylonitrile on a rubbery spine selected from polybutadieneand butadiene-styrene copolymer, and (II) separately preparedalpha-methylstyrene-acrylonitrile resin.
 15. A composition as in claim14 in which (C) is hexabromobenzene.
 16. A composition as in claim 14 inwhich (C) is hexabromodiphenylether.
 17. A composition as in claim 14 inwhich (C) is hexabromobenzene and antimony oxide.
 18. A composition asin claim 14 in which (C) is hexabromodiphenylether and antimony oxide.19. A composition as in claim 7 in which (B) contains separatelyprepared alpha-methylstyrene-acrylonitrile resin.
 20. A composition asin claim 19 wherein (A) amounts to 48-60 parts and (B) amounts tocorrespondingly 52-40 parts, and the bromo-aryl compound ishexabromobenzene.
 21. A composition as in claim 19 wherein (A) amountsto 48-60 parts and (B) amounts to correspondingly 52-40 parts, and thebromo-aryl compound is hexabromodiphenylether.